Matrix t*K(1) in Subspace 91 with Dimension 4

(K(1) is the first-order Grosse operator)

0 ((3 + I*Sqrt[3])*U)/Sqrt[2] (I*(3*I + Sqrt[3])*t)/Sqrt[2] 0
(I*(3*I + Sqrt[3])*U)/Sqrt[2] (-I)*Sqrt[3]*t ((3 + I*Sqrt[3])*U)/2 (I*(3*I + Sqrt[3])*t)/Sqrt[2]
((3 + I*Sqrt[3])*t)/Sqrt[2] (I/2)*(3*I + Sqrt[3])*U (-I)*Sqrt[3]*t 0
0 ((3 + I*Sqrt[3])*t)/Sqrt[2] 0 0